1. Field of the Invention
The present invention relates to a dye compound and an ink containing the dye compound.
2. Description of the Related Art
Dyes used for ink jet recording liquids (inks) are usually water-soluble dyes; however, there is a problem in that images printed with inks containing the water-soluble dyes are inferior in storage stability. That is, the images have problems such as low light resistance and low gas resistance and therefore are discolored by light such as sunlight or illumination light or oxidizing gases, such as ozone, NOx, and SOx, slightly contained in air.
In order to solve the problems, PCT Japanese Translation Patent Publication No. 2003-510398 (hereinafter referred to as Patent Document 1) discloses a pyridone azo compound for use as an ink jet water-soluble dye.
Japanese Patent Publication No. 37-006280 (hereinafter referred to as Patent Document 2) discloses 6-phenylazo-5-triazolo[2,3-a]pyrimidine. Germany Patent No. 2623839 (hereinafter referred to as Patent Document 3) discloses a dye compound with a 3-aryl-4-hydroxy-2-oxopyrimido[2,1-b]benzoimidazole structure.